Global warming may cause earthquakes

Hard to believe but read the artical
Melting Ice Sheets Can Cause Earthquakes, Study Finds

As ice sheets melt, they can release pent-up energy and trigger massive earthquakes, according to new study.

Global warming may already be triggering such earthquakes and may cause more in the future as ice continues to melt worldwide, the researchers say.

A series of large earthquakes shook Scandinavia around 10,000 years ago, along faults that are now quiet, the scientists point out.

The timing of each earthquake roughly coincided with the melting of thick ice sheets from the last ice age in those same places.

Researchers had suspected that the melting had triggered these earthquakes by releasing pressure that had built up in Earth’s crust.

Now a new study, the first to use sophisticated computer models to simulate how ice sheets would affect the crust in the region, bolsters this scenario.

The study showed that earthquakes are “suppressed in presence of the ice and promoted during melting of the ice,” said study leader Andrea Hampel of the Ruhr University Bochum in Germany.

Hampel and a colleague had earlier found evidence that the shrinkage of a huge lake at the end of the last ice age had triggered a series of large earthquakes in Utah.

The new study shows this can happen even along faults that are normally quiet and are not prone to slip.

The new research will be published soon in the journal Earth and Planetary Science Letters.

“With our new modeling technique we can model faults themselves and directly compare the slip on the model fault to the slip on natural faults,” Hampel said.

The models showed that thick ice could weigh down the land, preventing a fault from slipping and thereby causing it to store up that energy.

The thicker the simulated ice sheets—from 325 to 6,500 feet (100 to 2,000 meters) thick—the more they suppressed earthquakes, and the bigger the earthquakes were after the ice sheets melted.

Since the amount of movement on the fault in the model matched the actual amount of slippage measured in the field, this supports the idea that the melting of ice sheets had triggered the earthquakes, Hampel said.